Method of distributing skin care products

ABSTRACT

The present invention relates to a method of distributing a skin care product to a subject, the method including the steps of: (a) obtaining a sample of interstitial fluid from the skin of the subject; (b) measuring the amount of a skin analyte in the sample; and (c) distributing a skin care product to the subject to alter the amount of the skin analyte in the skin of the subject.

FIELD OF THE INVENTION

[0001] The present invention relates to a method of distributing a skincare product to a subject.

BACKGROUND OF THE INVENTION

[0002] Dermal interstitial fluid is a clear, water-like fluid presentbetween the cells in the living skin tissues (i.e., epidermis anddermis) under the stratum corneum. The composition of the interstitialfluid is substantially free of blood cells, but does contain smallmolecules and proteins. Interstitial fluid both transports nutrients(e.g., glucose) from the blood to the skin cells and removes cellularmetabolic wastes (e.g., urea) from the skin cells to the blood. Variouscomponents of the interstitial fluid are in equilibrium with livingcells in both the epidermis and dermis as well as macromolecularstructures located in the subcutaneous tissue.

[0003] The correlation of certain endogenous chemicals between the bloodand interstitial fluid has been well established. For example, Serviceet al. used a novel minimally invasive technique to sample minusculeamounts (0.5 microliter) of the interstitial fluid from both healthyvolunteers and diabetic patients. See Service et al., Diabetes Care, 20:9, 1426-9 (1997). Service et al. assessed the accuracy of the glucoseconcentrations in the interstitial fluid in predicting concurrentlymeasured venous plasma and capillary plasma glucose concentrations.Service et al. concluded that interstitial fluid sampling was abloodless, minimally invasive technique that provided a medium forglucose measurement, the concentrations of which closely reflectedambient glycemia to a degree comparable with that of capillary glucosemeasurements. A similar conclusion was also drawn by Krogstad et al.,British Journal of Dermatology, 134:6, 1005-12 (1996).

[0004] Others have also studied the concentration changes of certaindrugs in the interstitial fluid following oral administration. See,e.g., Zimmerli et al., Antimicrobia. Agents. Chemother, 40:1, 102-4(1996) and Vaillant et al., Eur. J. Clin. Pharmcol. 33:5, 529-30,(1987).

[0005] Although sampling interstitial fluid by minimally invasivetechniques for diagnostic applications to monitor diseases such asdiabetes is known, Applicant has found that certain endogenoussubstances present in the skin tissues (such as vitamin C) are at adifferent concentration in the interstitial fluid than in serum. Thus,analysis of substances in the serum is not indicative of thecorresponding concentration levels of such substances in the skin. Also,Applicant has also found that the concentration of certain endogenoussubstance in the interstitial fluid varies as a result of diet, aging,or the effect of external aggressions. Applicant has discovered that thedetermination of the concentration of certain endogenous substancespresent in the interstitial fluid, thus, can be used to assess thehealth of a subjects skin, permitting the administration of cosmetic orpharmaceutical agents to specifically treat the needs of the subject'sskin.

SUMMARY OF THE INVENTION

[0006] In one aspect, the invention features a method of examining skinhealth in a subject, the method including the steps of: accessing asample of interstitial fluid from the skin of the subject; and measuringthe amount of a skin analyte in the sample.

[0007] In one aspect, the invention features a method of diagnosing theskin health in a subject, the method including the steps of: (a)accessing a sample of interstitial fluid from the skin of the subject;(b) measuring the amount of a skin analyte in the sample; and (c)comparing the amount of the skin analyte to a reference standard.

[0008] A method of treating the skin of a subject, the method includingthe steps of: (a) accessing a sample of interstitial fluid from the skinof the subject; (b) measuring the amount of a skin analyte in thesample; and (c) applying a skin care product to the subject to alter theamount of the skin analyte in the skin of the subject.

[0009] A method of distributing a skin care product to a subject, themethod including the steps of: (a) obtaining a sample of interstitialfluid from the skin of the subject; (b) measuring the amount of a skinanalyte in the sample; and (c) distributing a skin care product to thesubject to alter the amount of the skin analyte in the skin of thesubject.

[0010] Other features and advantages of the present invention will beapparent from the detailed description of the invention and from theclaims.

DETAILED DESCRIPTION OF THE INVENTION

[0011] It is believed that one skilled in the art can, based upon thedescription herein, utilize the present invention to its fullest extent.The following specific embodiments are to be construed as merelyillustrative, and not limitative of the remainder of the disclosure inany way whatsoever.

[0012] Unless defined otherwise, all technical and scientific terms usedherein have the same meaning as commonly understood by one of ordinaryskill in the art to which the invention belongs. Also, all publications,patent applications, patents, and other references mentioned herein areincorporated by reference.

[0013] Definitions

[0014] What is meant by “examining skin health” is obtaining informationregarding the current biological condition of the skin. Suchinformation, for example, may provide insight into the current health ofthe skin (e.g., to determine whether certain cosmetic or pharmaceuticalskin treatments are necessary) as well as provide insight regarding theresponse of the skin to external trauma or treatment. In one embodiment,the information is obtained on a periodic basis, e.g., once a year, oncea month, once a week, or once a day, to continually monitor skin health.

[0015] What is meant by “skin analyte” is a chemical entity present inthe interstitial fluid of the skin that either participates in thebiological processes of the skin or is a product of such processes. Inone embodiment, the skin analyte is an endogenous substance. In oneembodiment, the skin analyte is an exogenous substance that entered theskin intentionally or unintentionally, which may exert desirable orundesirable biological effects on the skin.

[0016] Interstitial Fluid

[0017] The present invention relates to a method of examining skinhealth in a subject by obtaining a sample of interstitial fluid from theskin of said subject (e.g., a mammalian subject such as a human). Whatis meant by “interstitial fluid” is the clear fluid present between thecells in the living epidermis and dermis, which is substantially free ofblood cells.

[0018] Creation of Openings in the Skin

[0019] The epidermis and dermis are protected by the stratum corneum,which is a barrier layer of keratinized skin cells and lipids. Thus, inorder to gain access to interstital fluid, one must permeabilize thestratum corneum to access the interstitial fluid from the skin. In oneembodiment, the method of obtaining such sample of interstitial fluidcomprises creating an opening in the stratum corneum of the skin of saidsubject and obtaining said sample through the opening. In oneembodiment, the opening is also within the epidermis of the subject.Although not preferred, in one embodiment the opening is also within thedermis of said subject. Preferably, the opening results in minimalresidual tissue damage in order not to alter the composition of theinterstitial fluid. For example, creating a blister on the skin and thensampling the resulting interstitial fluid in the blister is notpreferred.

[0020] In one embodiment, about 1 to about 1000 openings are created inthe skin of the subject, such as about 2 to about 50 openings. In oneembodiment, the width of the opening is about 1 to about 500 microns,such as about 50 to about 250 microns. In one embodiment, the depth ofthe opening is about 50 to about 500 microns, such as about 75 to about200 microns. The number and size of openings will depend on the subjectbeing treated and the area of skin being analyzed.

[0021] In one embodiment, the opening is created by a mechanical device.Examples of such mechanical devices include, but are not limited to,hollow and solid needles, micro styluses, trochars, blades, and lancets.In one embodiment, such devices have an external diameter or width of upto 1 mm, such as bout 10 and about 200 microns. In one embodiment, themechanical device creates an opening either by piercing or scraping thestratum corneum. Examples of such mechanical devices can be found in PCTPatent Applications Nos. WO 95/10223, WO 98/11937, WO 97/48440, WO97/10745, WO 97/08987, W098/00193, WO 00/35530, WO 00/74763, WO00/74764, WO 00/74766, and WO 01/28423; U.S. Pat. Nos. 5,250,023,5,885,211, and 5,843,114; and Henry et al., Journal of PharmaceuticalSciences, Vol. 8, p. 922-25 (August, 1998).

[0022] In one embodiment, the opening is created by a heating device.Examples of heating devices include, but are not limited to, heatedelements (e.g., an ohmic heating element such as a wire heated byelectric current), lasers, and focused light beams of multiplewavelengths. In a further embodiment, a dye that exhibits an absorptionof light over the emission range of the laser or focused light beam isfirst applied to the skin such that the dye is heated sufficiently tocreate the opening. Examples of such heated elements, laser, and focuseslight beams are disclosed in U.S. Pat. Nos. 5,885,211, 5,155,992, and6,056,738; and PCT Patent Application Nos. WO 99/40848, WO 99/27852, WO99/20181, WO 97/42888, and WO 99/59485.

[0023] In one embodiment, a beam of sonic energy is used to create theopening in the stratum corneum. Examples of such sonic devices and/orthe use thereof to create openings in the stratum corneum are disclosedin U.S. Pat. Nos. 5,445,611, 5,458,140, and 5,885,211.

[0024] In one embodiment, a short pulse of electricity is used to createthe opening in the stratum corneum. Examples of such use can be found inU.S. Pat. No. 5,885,211.

[0025] In one embodiment, a high pressure jet of a fluid, gas, orparticulate is used to create the opening in the stratum corneum.Examples of the use of such high pressure jets can be found in U.S. Pat.No. 5,885,211.

[0026] In one embodiment, an electric arc is used to create the pore inthe stratum corneum. Examples of such a device and the use of such adevice to create an opening in the stratum corneum is disclosed in PCTPatent Application No. WO 01/13989.

[0027] In one embodiment, electromagnetic radiation is used to disruptthe stratum corneum in order to create openings to access theinterstitial fluid. Examples of such uses are set forth in Tope,Dermatol Surg 25:348-52 (1999).

[0028] Although not preferred, in one embodiment, a suction blister iscreated on the skin, and the roof of the blister is pieced or removed toobtain the interstitial fluid within the blister. An example of such adevice and the use of this device to so obtain interstitial fluid isdisclosed in Evedman, Pharm. Res., 15:6, 883-8 (1998).

[0029] Accessing Interstitial Fluid

[0030] In one embodiment, a sample of the subject's interstitial fluidis extracted by various means known in the art. Examples include, butare not limited to: a mechanical suction device with the structuresimilar to a syringe; a manual mechanical suction device using a pistonand a series of one-way valves with the working mechanism similar tocommercial apparatuses such as MityVac II® vacuum pump (PrismEnterprises, San Antonio, Tex., USA) and Aspivenin® (ASPIR, Sannois,France); a small size motor-driving suction/vacuum pump; a rubberpipeting suction bulb such as Bel-Bulb® Pipettor (Bel-Art Products,Inc., NJ, USA) and Welch® Suction Cup Electrode (Hewlett Packard,Rockville, Md., USA); a pre-manufactured vacuum chamber with the workingmechanism similar to the Vacumtainer® (Becton, Dickinson and Company,Franklin Lakes, N.J.); and a battery-driven suction device for cleaningof facial skin pores such as Panasonic EH2591s Pore Cleanser (MatsushitaElectric Works, Ltd. Osaka, Japan).

[0031] Kneading or vibration or pressure mechanism may be used togetherwith such suction devices to manipulate the skin around the opening tofacilitate the collection of the interstitial fluid. Example of suchmethods can be found in PCT Patent Application Nos. WO 97/428882 andWO97/08987. A method of heating the skin around the opening may also beused, with or without suction, to facilitate the interstitial fluidcollection. Such an example can be found in U.S. Pat. No. 6,155,992.Other methods of enhancing the extraction of interstitial fluid includeiontophoresis as well as the use of sonic energy and ultrasound. Such anexample can be found in PCT Patent Application Nos. WO 00/549,240 and WO97/04832, U.S. Pat. No. 6,173,202, and European Patent Application1,098,589.

[0032] To enable a speedy extraction of interstitial fluid with minimaldiscomfort when a mechanical suction device is used, the suction forcemay be within the range of 5-75 cm Hg (e.g., 20-60 cm Hg).

[0033] Alternative methods for obtaining interstitial fluid includeplacing on the opening(s) a capillary tube or an absorbent material(e.g., gauze or non-woven pad, sponge, hydrophilic polymers of porousstructure). For example, interstitial fluid can be extracted using anosmotic pressure by contacting the skin (e.g., skin in which the stratumcorneum has been compromised as stated above) with a hygroscopicmaterial such as glycerin, glycols such as polyethylene glycols andpolypropylene glycols, urea, or polyvinylidone. Other examples includeinserting an optical fiber within the opening to register lightinteraction with an analyte. See PCT Patent Application No. WO 99/07277.

[0034] In one embodiment, a permeation enhancer is used to enhance theextraction of the interstitial fluid. Examples of permeation enhancersinclude, but are not limited to, dimethyl sulfoxide, sodium hydroxide,dimethylamino ethanol, butanol, propylene glycol, oleic acid, and azone.Examples of permeation enhancers are disclosed in U.S. Pat. Nos.5,458,140, 5,445,611, 4,775,361, and 4,863,970.

[0035] In one embodiment, the interstitial fluid is collected in thesame device that created in the opening in the stratum corneum (e.g., adevice that comprises (i) a mechanical device or a heating device tocreate the opening in the stratum corneum and (ii) a vacuum device toextract a sample of the interstitial fluid). In a further embodiment,the device is further capable of measuring the concentration of the skinanalyte(s) in the collected sample as described below (e.g., using asensor for the analyte).

[0036] Analysis of Skin Analytes

[0037] After the interstitial fluid has be accessed (e.g., through theopening(s) created in the stratum corneum by one or more of the methodsdescribed above), the concentrations of a skin analyte(s) in theinterstitial fluid can be measured with standard analytical methodsknown in the art such as assays based on enzymatic reaction, antibodyinteraction, ion-selective electrode, oxidation-reduction electrode;infrared (IR), ultraviolet (UV) spectrophotometry, colorimetry, genearray technology, and gene amplification. Examples of such assays aredescribed in “Sensors in Biomedical Applications” by Gabor, TechnomicPub Co, Lancaster, Pa., 2000; and “Novel Approaches in Biosensors andRapid Diagnostic Assays” edited by Liron et al, Plenum Pub Corp, NewYork, 2000.

[0038] Alternatively, analysis of the biological substances of interestin the interstitial fluid may be performed through the opening createdby placing an analytical instrument (e.g., an infrared or ultravioletspectrophotometer) directly over the opening, without actuallyextracting the interstitial fluid out of the skin.

[0039] The present invention relates to a method of measuring the amountof biochemical component in said sample (herein referred to as a “skinanalyte”). The skin analyte is substance which will provide feedback asto the health of the skin, e.g., provide a marker for possible skindisorders such as but not limited to: intrinsic skin aging, wrinkles,acne, photodamage, rosacea, scars, hypertrophic scars, keliods, stretchmarks or striae distensiae, psoriasis, nutrient status, anti-oxidantstatus, energy status, oxygen status, eicosanoid staus, leukotrienestatus, pruritus, ehlers-danlos syndrome, scleroderma, post inflammatoryhyperpigmentation, melasma, alopecia, poikiloderma of civatte, viteligo,skin cancers, skin dyschromas or blotchy pigmentation.

[0040] In one embodiment, the skin analyte is predominantly found in theskin. Examples of such skin analytes include, but are not limited to,enzymes such as the family of matrix metalloproteinases such as MMP 1through MMP-13, stromolysin, elastase, glucosylceramide synthetase, andglutathione peroxidase; antibodies that demonstrate status of a skindisorder; macromolecules such as the collagen family of proteins such ascollagen I through collagen XVIII, elastin, keratins, andglycosaminoglycans; the integrin family of matrix receptors such asintegrins type alpha 2 through 10 and integrins type beta 1 through 8;cytokines such as insulin-like growth factors such as IGF-1 and tissueinhibitor of matrix proteinases; and derivatives thereof.

[0041] Other skin analytes include, but are not limited to, enzymes suchas B-galactosidase, ALA and ASP transferase, protein kinase C, NOsynthetase, ornithine decarboxylase, ubiquitin-conjugating enzymes,phosolipid hydroperoxide, death associated protein kinase, DAP kinase orother serine-threonine kinases involved in cellular apoptosis, andsuperoxide dismutase; macromolecules such as hylauronic acid,fibronectin, fibrin, basement membrane components including laminin andtype IV collagen; cytokines such as platelet derived growth factor,keratinocyte growth factor, epidermal growth factor, fibroblast growthfactors, connective tissue growth factor, transforming growth factorbeta such as TGF-β 1 through TGF-β 3, Vascular endothelial growthfactor, growth hormone, tissue plasminogen activator or plasminogenactivator tissue type or urokinase type, tissue plasimogen activatorinhibitor, plamasinogen activator inhibitor type I and II, interleukinssuch as IL-1α, heat shock proteins, thrombospodin, the family ofComplement glycoproteins, and interferons; immunoglobulins such as IG-G,IG-A, and IG-E; inflammatory mediators such as prostaglandins, dihydroxytestosterone, leukotrienes, histamine, substance P, and tumor necrosisfactor; hormones such as estrogens, phytoestrogens, testosterones suchas dihydroxytestosterone, melanocyte stimulating factor,adrenocorticotropic hormone, and urocortin; antioxidants such asvitamins (e.g., vitamins A, Bs, C, and E), polyphenols, and leukopene;coenzyme Q-10; and CEHC, and derivatives thereof.

[0042] In one embodiment, the concentration of such skin analyte iscompared to a reference standard for such skin analyte, e.g., todetermine whether such concentrations are above or below normalconcentration levels for such subject. In one embodiment, suchdetermination may indicate whether such patient is suffering or at riskfor suffering from a skin disorder. In one embodiment, suchdetermination may indicate whether current treatment of a skin disorderis effective, or it may indicate whether a future treatment regimen maybe effective.

[0043] Diagnosis of Subject

[0044] In one embodiment, the subject is a mammal such as a human. Themethod of the present invention may be used on both healthy subjects(e.g., to ensure their skin health) as well as subjects who areinflicted at various stages with a skin disorder, including but notlimited to intrinsic skin aging, wrinkles, acne, photodamage, rosacea,scars, hypertrophic scars, keliods, stretch marks or Striae distensae,psoriasis, nutrient status, anti-oxidant status, energy status, oxygenstatus, eicosanoid staus, leukotriene status, pruritus, ehlers-danlossyndrome, scleroderma, post inflammatory hyperpigmentation, melasma,alopecia, poikiloderma of civatte, viteligo, skin cancers, skindyschromas, or blotchy pigmentation.

[0045] As many skin disorders are not always visibly apparent (e.g.,early stage photodamage to the skin), the methods of the presentinvention provide a means for early diagnosis of such skin disorders.The patient and/or doctor, thus, can then attempt to treat suchdisorders at an early stage before such disorders are visuallymanifested. In one embodiment, the method of the present invention mayalso be used to determine whether a certain skin treatment would beeffective or whether a skin treatment is stabilizing, alleviating,and/or curing the skin disorder.

[0046] For example, a subject can be analyzed to determine whether ithas adequate levels of minoxidil synthase in its skin prior toinitiation of treatment with minoxidil. Another example is the use ofmonoclonal antibodies to TNF-α as a treatment for psoriasis. High levelsof TNF-α have been implicated in the presence and severity of psoriaticplaques. Treatment with the monoclonal antibody inhibits the action ofTNF-α and results in the resolution of the plaque. Continued measurementof the ratio of TNF-α to MABTNF-α may predict the necessity of treatmentin order to maintain the disease in a quiescent state. The use of thepresent invention would allow measurement of the antigen/antibody levelin the skin, which may provide a more accurate assessment of thecondition than the same measurement taken from circulating systemicblood.

[0047] Thus, such monitoring using the methods of the present inventionmay decrease the cost, side effects, and inconvenience of a typicaltimed regimen, thereby, improving the quality of life of the patient.

[0048] Skin Care Compositions

[0049] Following analysis of the interstitial fluid, a skin carecomposition can be administered to the subject to address any problemsidentified following the analysis of the skin analytes. In oneembodiment, a skin care product is administered, e.g., by the subject ora doctor, to said subject to alter the amount of said skin analyte inthe skin of the subject.

[0050] What is meant by a “skin care product” is a topical compositioncomprising cosmetically active agent. What is meant by a “cosmeticallyactive agent” is a compound (e.g., a synthetic compound or a compoundisolated from a natural source) that has a cosmetic or therapeuticeffect on the skin, including, but not limiting to, anti-aging agents,lightening agents, darkening agents such as self-tanning agents,anti-acne agents, shine control agents, anti-microbial agents,anti-inflammatory agents, anti-mycotic agents, anti-parasite agents,anti-cancer agents, agents for photodynamic therapy, steroids, externalanalgesics, sunscreens, photoprotectors, antioxidants, keratolyticagents, detergents/surfactants, moisturizers, nutrients, amino acids,amino acid derivatives, minerals, plant extracts, animal-derivedsubstances, vitamins, energy enhancers, anti-perspiration agents,astringents, deodorants, hair removers, hair growth stimulators, hairgrowth retarding agents, firming agents, anti-callous agents, and agentsfor hair, nail, and/or skin conditioning.

[0051] In one embodiment, the agent is selected from, but not limitedto, the group consisting of hydroxy acids, benzoyl peroxide, sulfurresorcinol, ascorbic acid, D-panthenol, hydroquinone, octylmethoxycinnimate, titanium dioxide, octyl salicylate, homosalate,avobenzone, polyphenolics, carotenoids, free radical scavengers, spintraps, retinoids such as retinol and retinyl palmitate, ceramides,polyunsaturated fatty acids, essential fatty acids, enzymes, enzymeinhibitors, minerals, hormones such as estrogens, steroids such ashydrocortisone, 2-dimethylaminoethanol, copper salts such as copperchloride, peptides containing copper such as Cu:Gly-His-Lys, coenzymeQ10, peptides such as those disclosed in PCT Patent Application No. WO00/15188, lipoic acid, amino acids such a proline and tyrosine,vitamins, lactobionic acid, acetyl-coenzyme A, niacin, riboflavin,thiamin, ribose, electron transporters such as NADH and FADH2, and otherbotanical extracts such as aloe vera and legumes such as soy beans, andderivatives and mixture thereof. The cosmetically active agent willtypically be present in the composition of the invention in an amount offrom about 0.001% to about 20% by weight of the composition, e.g., about0.01% ot about 10% such as about 0.1% to about 5%.

[0052] Example of vitamins include, but are noet limited to, vitamin A,vitamin Bs such as vitamin B3, vitamin B5, and vitamin B12, vitamin C,vitamin K, and vitamin E and derivatives thereof.

[0053] Examples of hydroxy acids include, but are not limited, toglycolic acid, lactic acid, malic acid, salicylic acid, citric acid, andtartaric acid. See, e.g., European Patent Application No. 273,202.

[0054] Examples of antioxidants include but are not limited to,water-soluble antioxdants such as sulfhydryl compounds and theirderivatives (e.g., sodium metabisulfite and N-acetyl-cysteine), lipoicacid and dihydrolicpoic acid, resveratrol, lactoferrin, glutathione, andascorbic acid and ascorbic acid derivatives (e.g., ascorbyl palmitateand ascorbyl polypeptide). Oil-soluble antioxidants suitable for use inthe compositions of this invention include, but are not limited to,butylated hydroxytoluene, retinoids (e.g., retinol and retinylpalmitate), tocopherols (e.g., tocoherol acetate), tocotrienols, andubiquinone. Natural extracts containing antioxidants suitable for use inthe compositions of this invention, include, but not limited to,extracts containing flavonoids and isoflavonoids and their and theirderivatives (e.g., genistein and diadzein), extracts containingresveratrol and the like. Examples of such natural extracts includegrape seed, green tea, pine bark, and propolis. Other examples ofantioxidants may be found on pages 1612-13 of the ICI Handbook.

[0055] Various other materials may also be present in the compositionsuseful in the subject invention. These include humectants, proteins andpolypeptides, amino acids, ion conjugated amino acids preservatives andan alkaline agent. Examples of such agents are disclosed in the ICIHandbook, pp. 1650-1667.

[0056] The compositions of the present invention may also comprisechelating agents (e.g., EDTA) and preservatives chelating agents arelisted in pp. 1626 and 1654-55 of the ICI Handbook. In addition, thetopical compositions useful herein can contain conventional cosmeticadjuvants, such as dyes, opacifiers (e.g., titanium dioxide), pigments,and fragrances.

[0057] Distribution of Skin Care Products

[0058] Skin care products may also be distributed to subjects based uponthe knowledge obtained for the measurement of a skin analyte in thesubject's interstitial fluid. For example, a skin care product may bedistributed to the subject to alter (e.g., increase or descrease) theamount of the skin analyte in the skin of the subject dxiretly orindirectly. Furthermore, a profile of specific analytes in the skin maybe more predictive of a disease or traumatic state of the skin that mayrequire a unique combination of ingredients delivered in a specificregimen. Thus, specific skin care products may be distributed tosubjects to address the subject's individual needs. As used herein,“distributing a skin care product” includes the giving, selling, as wellas providing a prescription, for a skin care product. Thus, retailestablishments can use the methods herein to sell skin care products tocustomers. Doctors, such as dermatologists, can use the methods hereinto both diagnose subjects who are suffering, or at risk of suffering,from a skin disorder, and provide the subject with a skin care productor a prescription for a skin care product.

[0059] The following is a description of the extraction and analysis ofvarious skin analytes from human subjects. Other methods of theinvention can be practiced in an analogous manner by a person ordinaryskill in the art.

EXAMPLE 1

[0060] The following two clinical studies were conducted to collectinterstitial fluid (“ISF”) from human subjects for the purpose ofmeasuring various skin analytes contained therein. The skin analytesvitamin C, interluekin -1α (“IL-1A”), and metalloproteinase-1 (“MMP-1”)were measured during the first clinical study (“Study 1”) while theanalytes vitamin C, immunoglobulin E (“IGE”), insulin-like growthfactor-1 (“IGF-1”)IL-1A, IL-1 receptor antagonist (“IL-1 RA”) and MMP-1were measured in the second clinical study (“Study 2”). It is believedthat these skin analytes may be predictive of the level of intrinsic orextrinsic skin aging.

[0061] The studies included non-smoking, male and female subjects ofgood health over the age of 35 years and under the age 55 years withskin type of III or less by the Fitzpatrick Skin classification. Study 1was conducted with 20 patients during the month of June while Study 2was conducted with 27 patients during the month of September. Subjectsin each study had the ISF removed from skin both on the dorsal arm(“sun-exposed area”) and from skin on the buttocks (“sun-protectedarea”). Patients were also sub-divided into groups who took vitamin Csupplements (e.g., orally taking multi-vitamins and/or vitamin C). Instudy 2, subjects were also suparated to those who had a high body massindex (BMI>=27) to see if available fluid in the skin made a differencein collection or concentration of recovered analytes.

[0062] The stratum corneum of th sites from which the ISF was removedwere first opened using a laser device which activates a dye on the skinsurface as described in U.S. Pat. No. 5,885,211. The device was obtainedfrom SpectRx Inc. (Norcross, Ga. 30071). The laser made four pores ateach collection site. Two collection sites were used in study 1 whilefour collection sites were used in study 2. These areas were shaven, ifnecessary, to remove any hair which may interfere with the procedure andthen prepped using a skin cleanser prior to poration.

[0063] Following poration of the stratum corneum, a hand held vacuumapparatus was attached to the site using an “A” style harvesting head.The head was attached to the skin with a medical grade adhesive. Thesample reservoir in the area over the opering was visually monitored totrack the ISF flow rate. ISF was collected into thin-walled medicaltubing, which allows for visual fluid quantification. The clear plastictubing also allowed the researcher to visually assess any sign ofredness or irritation and the presence of blood.

[0064] The ISF collection period lasted between 3 and 6 hours, typically4 hours. The amount of ISF collected during each of the studies are setforth in Tables 1 and 2, separated by the location of the skin tested.These results indicated that an increase in the number of openingsconsequently increased the volume of ISF collected as patients in Study1 received eight openings while those in Study 2 received sixteenopenings. Additionally this data suggests that the amount of fluidacquired is site dependent as it was found to be easier to extract fluidfrom the arm than from the buttock. TABLE 1 Study 1 Sample Volume ofInterstitial Fluid Sample Volume Sample Volume Arm (uL) Buttocks (uL)Mean 106.2 75.05 Standard Error 9.16 12.79 Median 100 65 Count 20 20

[0065] TABLE 2 Study 2 Sample Volume of Interstitial Fluid Sample VolumeSample Volume Arm (uL) Buttocks (uL) Mean 262 252 Standard Error 23 24Median 250 275 Count 27 27

[0066] Analysis of the data from study 1 indicates that IL-1A can bemeasured in as little as 10 microliters of interstitial fluid from skin.

[0067] Levels detected corroborate previous findings in the literaturesuggesting that sun-exposed skin has a lower concentration of 1L-1A thansun protected skin. Furthermore, the levels do not correlate withsupplementation or level of Vitamin C. On the other hand, twice as muchISF was necessary to detect levels of MMP-1 due to the lowerconcentration of the enzyme in skin. Data suggests that it is presentand is in a lower amount in sun protected skin of non-supplementedsubjects. It can be inferred that levels of MMP may fluctuate due to thedegree of photodamage and level of antioxidant present in the skinsuggesting that the level of Vitamin C may be a surrogate marker ofextrinsic skin aging.

[0068] Tables 3-6 report the results from the determination of theconcentration of vitamin C in these two studies. Vitamin C was measuredusing a standard assay described in the Laboratory Procedures Used bythe Clinical Chemistry Division, Centers for Disease Control, for theSecond Health and Nutrition Examination Survey (HANES II) 1976-1980,published by the U.S. Department of Health and Human Services, PublicHealth Services, Atlanta, Ga., pp. 17-19 (1979).

[0069] The results of Study 1 are depicted in Tables 3 and 4, separatedby (i) the location of the skin tested and (ii) whether subjects whotook vitamin C supplements. TABLE 3 Concentration of Vitamin C in SunProtected Skin ISF (Non-supplemented Vs Supplemented) Vitamin C, VitaminC, Non-supplemented Supplemented (Buttocks) (Buttocks) (mg/dl) (mg/dl)Mean 1.50 1.71 Standard 0.19 0.22 Error Median 1.52 1.44 Count (F = 4, M= 5) (F = 1, M = 4)

[0070] TABLE 4 Concentration of Vitamin C in Sun Exposed Skin ISF(Non-supplemented Vs Supplemented) Vitamin C, Vitamin C,Non-supplemented Supplemented (Arm) (mg/dl) (Arm) (mg/dl) Mean  1.10*1.69 Standard 0.09 0.23 Error Median 1.18 1.58 Count       (F = 7, M =6) (F = 3, M = 6)

[0071] These results of Tables 3 and 4 demonstrate that detectablelevels of vitamin C can measured from ISF.

[0072] Also, a significant difference was found between sun exposed skin(arm) depending on supplementation. The results also found that theamount of vitamin C was significantly less in the arm ofnon-supplemented subjects than in the arm of supplemented subjects,indicating that vitamin C supplements increase the is endogenousconcentration of Vitamin C present in ISF.

[0073] The results of Study 2, which examined vitamin C concentration aswell as other analytes, are set forth in Table 5-10. TABLE 5Concentration of Vitamin C in ISF from Subjects Not Taking Oral VitaminSupplements Vitamin C, Vitamin C, Vitamin C, Supplemented SupplementedSupplemented (Buttocks) (Arm) (Serum) (mg/dl) (mg/dl) (mg/dl) Mean 0.590.59 0.72 Standard 0.11 0.18 0.13 Error Median 0.69 0.52 0.74 Count 9 99

[0074] TABLE 6 Concentration of Vitamin C in ISF from Subjects TakingOral Vitamin Supplements Vitamin C, Vitamin C, Vitamin C, SupplementedSupplemented Supplemented (Buttocks) (Arm) (Serum) (mg/dl) (mg/dl)(mg/dl) Mean 1.223 1.1326 1.558 Standard 0.091 0.094 0.122 Error Median1.231 1.151 1.615 Count 18 17 18

[0075] The results of Tables 5 and 6 also indicate that detectablelevels of vitamin C were measured in ISF. The results also discoveredthat the amount of vitamin C in the ISF was not the same as the amountpresent in serum, thus, indicating that the a serum measurement ofvitamin C is not indicative of its concentration within the skin. Theamount of vitamin C measured in Study 2 was also different from thatmeasured in Study 1, indicating the possible seasonal effect (e.g., sunexposure) on the concentration of vitamin C in the skin.

[0076] The other skin analytes were measured in Study 2 using standardELISA kits: MMP-1 (ELISA Cat # QIA55, Oncogene Research Products,Cambridge Mass.); Total IgE (ELISA Cat # RE59061, IBL, Hamburg, Germanydistributed by KMI Diagnostics); Non Extraction IGF-1 (ELISA Cat #DSL-10-2800, Diagnostics Systems Laboratories, Webster Tex.); IL-1 RA(ELISA Cat # DRA00, R&D Systems, Minneapolis, Minn.); IL-LA (ELISA Cat #EH2IL1A, Pierce/Endogen, Rockford, Ill.). Tables 7-8 reports on theconcentration of these analytes. TABLE 7 Concentration of Skin MarkersCollected from Sun-exposed and Sun-protected Areas Collection SiteSun-exposed Sun-protected N MEAN STD N MEAN STD IgE (log) 21 3.01 9.6519 12.62 7.4 IGF-1 24 77.84 29.42 20 92.73 31.97 IL-1A 26 98.59 5.68 26182.9 3.33 (log) IL-1 RA 27 9902 1.66 27 9552 1.65 (log) MMP-1 25 0.621.79 23 0.82 2.09 (log)

[0077] TABLE 8 Effect of Supplementation on the Concentration of SkinMarkers Collected from Sun-exposed and Sun-protected Areas Supplement NoYes Site Marker N MEAN STD N MEAN STD Sun- Vitamin C 4 0.55 0.18 23 1.000.55 exposed IgE (log) 4 0.37 4.89 17 4.94 8.50 IGF-1 4 82.85 28.83 2076.83 30.17 IL-1A 4 33.08 52.0 22 120.24 2.84 (log) IL-1 RA 4 8660 1.6023 10140 1.68 (log) MMP-1 4 0.51 1.95 21 0.64 1.78 (log) Sun- Vitamin C4 0.67 0.28 23 1.00 0.45 protected IgE (log) 2 0.49 9.47 17 18.50 5.20IGF-1 2 47.27 4.34 18 97.78 29.52 IL-1A 4 141.8 15.3 22 191.5 2.22 (log)IL-1 RA 4 9899 1.46 23 9492 1.70 (log) MMP-1 3 0.41 3.47 20 0.91 1.85(log) Serum Vitamin C 4 0.82 0.22 23 1.36 0.63

[0078] The results of Tables 7 and 8 indicate that detectable levels ofvitamin C can be measured in ISF.

[0079] The results of Study 2 also indicated that sun-protected area hadsignificantly (p<0.01) higher levels of IgE, IL-1A, and MMP-1. Also theresults revealed that vitamin C supplement significantly increased theconcentration of vitamin C as well as IgE, IL-1A, IL-1 RA, and MMP-1 inISF. The study also indicated that males have significantly higherconcentrations of IgE, IGF-1, and IL-1 RA, and women had significantlyhigher concentration of IL-1A. The study also indicated that subjectswith a high BMI had higher concentration of IgE.

[0080] The results of Study 2 also indicated that sun-exposed andsun-protected values were positively correlated for all values exceptIGF-1 (i.e., as the sun-exposed values increase, in general, thesun-protected values increase as well). Vitamin C levels from thesun-protected area were also positively correlated with age, implyingthat Vitamin C levels increase as people age in tissues that are notexposed to oxidative stress. The results also indicated that among thosesubjects who do not supplement, a very strong negative correlationexists between Vitamin C and MMP-1 for both sun-exposed andsun-protected areas (i.e., as Vitamin C goes up, MMP-1 goes down).

EXAMPLE 2

[0081] The following clinical study was performed to demonstrate theconcept of application of a bioactive material and the subsequentmonitoring of the substance thereafter.

[0082] The studies included non-smoking, female subjects of good healthover the age of 35 years and under the age 55 years with skin type ofIII or less by the Fitzpatrick Skin classification. Additionally,subjects did not take any vitamin, nutritional or mineral supplementorally or topically. Interstitial fluid was analyzed for Vitamin C inorder to identify a specific population of subjects within approximatelyone standard deviation of the mean of all potential candidates tested.Acceptable subjects were chronologically enrolled in the study followinga randomization code describing what treatment would be applied to whichdorsal forearm. Treatments included a high and a moderate concentrationof Vitamin C in a topical emulsion. These were compared to each other aswell as to the emulsion without Vitamin C. The subject applied a blindedemulsion designated by a letter to one dorsal forearm and an alternativeemulsion with a different designation to the opposite arm, twice perday, for three weeks. Vitamin C levels were measured from an aliquot offluid acquired from the skin and the serum. ISF was extracted from thedorsal forearm, volar upper arm, and serum at one week (“Week 2”) andthree weeks after dosing (“Week 4”) and two weeks after the cessation ofdosing (“Week 6”).

[0083] ISF was extracted from both the treatment site (dorsal forearm)as well as an adjacent, untreated site volar upper arm) following oneweek of therapy and three weeks of therapy. Subjects ended treatment atthis point and returned for a final extraction two weeks later.

[0084] The ISF was removed using the same procedure described in Example1 with the device making four pores at each collection site. The ISFcollection period lasted between three and six hours, typically fourhours. Vitamin C was measured using a standard assay described in theLaboratory Procedures Used by the Clinical Chemistry Division, Centersfor Disease Control, for the Second Health and Nutrition ExaminationSurvey (HANES II) 1976-1980, published by the U.S. Department of Healthand Human Services, Public Health Services, Atlanta, Ga., pp. 17-19(1979).

[0085] Results presented in Table 9 demonstrate that application oftopical Vitamin C in either high dose or moderate dose modulates thelevel of Vitamin C at the application site in a dose dependent mannerthat is significantly different than the placebo that did not containVitamin C. The effect was maximal at the first week after therapy wasinitiated in the high dose treatment group and declined at week four.The moderate dose, however, appeared to stabilize at the concentrationachieved during the first week. All doses decreased to approximatebaseline values two weeks after ending therapy at week six. TABLE 9Concentration of Vitamin C (mg/dl ± STE) at the Application Site (dorsalforearm) High Dose Moderate Dose Placebo Baseline 0.95 ± .09 1.01 ± .090.91 ± .09 Week 2 3.32 ± .82 2.02 ± .73 0.85 ± .20 Week 4 2.02 ± .562.02 ± .89 0.89 ± .12 Week 6 1.15 ± .11 1.14 ± .07 1.09 ± .13

[0086] As shown in Table 10, further inspection of the subjects in thehigh dose treatment group demonstrated the immense variability ofsubject responses. Five of the patients could be considered respondersto therapy whereas the other five could be considered non-responders tothe therapy. This is an unexpected finding highlighting the necessity ofmonitoring of bioactive molecules in relation to the health of the skin.TABLE 10 Concentration of Vitamin C (mg/dl) at the Application Site(dorsal forearm) for the High Dose Group Baseline Week 2 Week 4 Week 6 10.94 1.55 1.73 1.57 2 1.1 1.43 1.42 1.22 3 1.19 8.32 1.3 1.32 4 1.085.53 3.55 1.1 5 0.37 5.71 5.92 0.38 6 1.15 0.95 1.37 1.24 7 0.66 0.58 NA1.21 8 1.14 1.33 0.71 1.14 9 0.68 4.05 0.62 1.16 10 1.22 3.78 1.53 NA

[0087] The results in Table 11 illustrate that treatment with a topicalapplication at one area of the body does not influence either levels atan adjacent, untreated site or the serum, suggesting that it is atreatment specific response at the doses tested. TABLE 11 Concentrationof Vitamin C (mg/dl ± STE) for High Dose Group Location Baseline Week 2Week 4 Week 6 Serum 0.69 ± 0.08 0.66 ± 0.12 0.75 ± 0.15 1.17 ± 0.11Adjacent Site ND 0.85 ± 0.12 0.90 ± 0.12 1.07 ± 0.11 (UV) Treatment Site0.95 ± 0.09 3.32 ± 0.82 2.02 ± 0.56 1.15 ± 0.11 (LD)

[0088] The results of this study suggest that application of abiologically molecule such as vitamin C can be measured by the methodsof the present invention and that due to subject variability this methodshould be implemented in order to achieve the desired dosingconcentration and regimen. The results indicate that using the method ofthe present invention is the preferred means to establish unique skinresponses directly effecting the health of the skin. The prior method ofserum monitoring is, as indicated above, ineffective in delineating thebiologically pertinent levels as seen below in Table 12. Regardless ofthe dose of vitamin C applied, the serum level did not respond totopical therapy at the concentrations applied. TABLE 12 Concentration ofVitamin C (mg/dl ± STE) in the Serum Treatment Group Baseline week 2week 4 week 6 High Dose 0.69 ± 0.08 0.66 ± 0.12 0.75 ± 0.15 1.17 ± 0.11Mid Dose 0.82 ± 0.08 0.76 ± 0.12 0.92 ± 0.13 1.24 ± 0.07 Placebo 0.72 ±0.11 0.67 ± 0.17 0.86 ± 0.13 1.14 ± 0.13

[0089] It is understood that while the invention has been described inconjunction with the detailed description thereof, that the foregoingdescription is intended to illustrate and not limit the scope of theinvention, which is defined by the scope of the appended claims. Otheraspects, advantages, and modifications are within the claims.

What is claimed is:
 1. A method of distributing a skin care product to asubject, said method comprising the steps of: (a) obtaining a sample ofinterstitial fluid from the skin of said subject; and (b) measuring theamount of a skin analyte in said sample; and (c) distributing a skincare product to said subject to alter the amount of said skin analyte inthe skin of said subject.
 2. A method of claim 1, wherein said methodcomprises creating a opening in the stratum corneum of the skin of saidpatient and accessing said sample through said opening.
 3. A method ofclaim 2, wherein said opening is created with a needle, a blade, alaser, or an electric arc.
 4. A method of claim 3, wherein said openingis created with a laser.
 5. A method of claim 2, wherein said sample isextracted through said opening under negative pressure.
 6. A method ofclaim 3, wherein said sample is extracted through said opening undernegative pressure.
 7. A method of claim 1, wherein said skin analyte isa vitamin, an immunoglobulin, an insulin-like growth factor, aninterleulin, an interleukin receptor antagonist, or a metalloproteinase.8. A method of claim 1, wherein said skin analyte is vitamin C.
 9. Amethod of claim 6, wherein said skin analyte is a vitamin, animmunoglobulin, an insulin-like growth factor, an interleulin, aninterleukin receptor antagonist, or a metalloproteinase.
 10. A method ofclaim 6, wherein said skin analyte is vitamin C.
 11. A method of claim1, wherein said method further comprises comparing the amount of saidanalyte is compared to a reference standard.
 12. A method of claim 2,wherein said method further comprises comparing the amount of saidanalyte is compared to a reference standard.
 13. A method of claim 4,wherein said method further comprises comparing the amount of saidanalyte is compared to a reference standard.
 14. A method of claim 6,wherein said method further comprises comparing the amount of saidanalyte is compared to a reference standard.
 15. A method of claim 10,wherein said method further comprises comparing the amount of saidanalyte is compared to a reference standard.
 16. A method of claim 1,wherein said skin care product comprises a vitamin.
 17. A method ofclaim 2, wherein said skin care product comprises a vitamin.
 18. Amethod of claim 4, wherein said skin care product comprises a vitamin.19. A method of claim 6, wherein said skin care product comprises avitamin.
 20. A method of claim 10, wherein said skin care productcomprises a vitamin.
 21. A method of claim 11, wherein said skin careproduct comprises a vitamin.
 22. A method of claim 12, wherein said skincare product comprises a vitamin.
 23. A method of claim 13, wherein saidskin care product comprises a vitamin.
 24. A method of claim 14, whereinsaid skin care product comprises a vitamin.
 25. A method of claim 15,wherein said skin care product comprises a vitamin.